1. Field of the Invention
The present invention relates to a siding boards attachment structure in which a siding board which has left and right shiplap or four sides shiplap is attached to an underlayment (for instance furring strips) using a securing metal fitting, and the invention also relates to a sealing member used therefor, a siding board and a method of attaching siding boards.
2. Discussion of the Background
Conventionally, there exists a siding boards attachment structure in which siding boards are attached to an underlayment and these siding boards are jointed with each other using shiplap joint structure on the left and right side or four side (left, right, upper and lower sides) of each siding board.
For example, a siding board 92 including a four side shiplap structure shown in FIG. 16 has an upper underlying tongue portion 922 formed on an upper side of the siding board 92, a lower overlying tongue portion 921 formed on a lower side of the siding board 92, a lateral underlying tongue portion 924 formed on a right side of the siding board 92 and a lateral overlying tongue portion 923 formed on a left side of the siding board 92. When upper and lower siding boards are jointed to each other, the lower overlying tongue portion 921 of the upper siding board 92 is superposed on the upper underlying tongue portion 922 of the lower siding board 92. When the left and right siding boards are jointed to each other, the lateral overlying tongue portion 923 of the right siding board 92 is superposed on the lateral underlying tongue portion 924 of the left siding board 92.
As shown in FIG. 16, usually, caulking material 929 is adhered on the flat surface of the upper underlying tongue portion 922 and the lateral underlying tongue portion 924 of the siding board 92. The back surfaces of lower overlying tongue portion 921 and the lateral overlying tongue portion 923 of one of the siding boards 92 press the caulking material 929 on the other siding boards, thereby preventing water from leaking from a gap of the joint portion of the siding boards 92.
In this case, the caulking material 929 is covered with the lower overlying tongue portion 921 or the lateral overlying tongue portion 923, and the caulking material 929 is not exposed from the front of the siding board. Therefore, it is possible to obtain a siding boards attachment structure which is excellent from the viewpoint of outward appearance design.
The siding boards 92 are fixed to each other using securing metal fittings 5. These securing metal fittings 5 are formed such that they can be fitted to an upper surface shape of the upper underlying tongue portion 922 and a back surface shape of the lower overlying tongue portion 921. These securing metal fittings 5 are disposed at connecting portions where four siding boards 92 are butted into one another so that each of the siding boards 92 is fixed to the underlayment such as furring strip mounted to a framework.
However, in actuality, even though the caulking material 929 for preventing inundation is adhered, an adverse possibility that rainwater and the like may be lead inside of the siding boards attachment structure 9 is not avoided completely.
That is, as shown in FIG. 17, rainwater 6 coming from a gap 927 of the joint portion between left and right two adjacent siding boards 92 is prevented from moving laterally (right in FIG. 17) by the caulking material 929, and the rainwater 6 passes through the gap 927 of the joint portion and falls downward.
However, the caulking material 929 adhered on the lateral underlying tongue portion 924 of the siding board 92 is not continuous in an opposed gap 928 to which the lateral underlying tongue portion 924 of the upper and lower siding boards 92. Therefore, when the rainwater 6 falling down through the gap 927 of the joint portion reaches the opposed gap 928, a portion of the rainwater 6 enters into the siding boards attachment structure 9.
More specifically, as shown in FIG. 18, in a construction state in which the securing metal fitting 5 is disposed at a corner of the siding board 92, the rainwater 6 falling down through the gap 927 of the joint portion passes through a front surface of a front flat plate 57 of the securing metal fitting 5, and further moves downward toward the gap 927 of the joint portion.
However, the front flat plate 57 is not necessarily in tight contact with the back surface of the lower overlying tongue portion 921 of the siding board 92 completely. Therefore, a portion of the rainwater 6 flows laterally through the front surface of the front flat plate 57 as shown in FIG. 18, falls on the upper underlying tongue portion 922 of the lower siding board 92 from a side end 59, and moves toward a backside of the siding board 92.
A portion of the rainwater 6 which has moved laterally through the front flat plate 57 moves laterally on a support portion 52 of the securing metal fitting 5 beyond the front flat plate 57, and moves toward a backside of the siding board 92 from the side end 59 of the securing metal fitting 5 similarly.
As a result, when the siding board 92 or the underlayment 3 is made of material having poor water resistance such as a ceramic type siding board or wood-based furring, this becomes a cause of corrosion and deterioration.
The rainwater 6 entering from the gap 926 of the joint portion of the upper and lower siding boards 92 is prevented from moving upward by the lateral caulking material 929 adhered on the upper underlying tongue portion 922, and is discharged forward from the wall surface.
Such an inconvenience can be naturally generated not only in the siding boards attachment structure which has four side shiplap joint, but also a siding boards attachment structure using siding boards having at least left and right shiplap structure.
An object of the present invention is to provide a siding boards attachment structure and a method of attaching siding boards capable of substantially preventing water from entering inside of the siding boards, and to provide a sealing member and a siding board used for the siding boards attachment structure.
According to one aspect of the invention, a siding boards attachment structure, includes siding boards, at least one underlayment, securing metal fittings and at least one sealing member. The siding board has opposite right and left sides and opposite upper and lower sides. The siding board is provided at the opposite right and left sides with a lateral underlying tongue portion and a lateral overlying tongue portion, respectively. The lateral underlying tongue portion protrudes along a direction from the left side to the right side in a back surface side. A notched recess is notched along a direction from the right side to the left side in front of the lateral underlying tongue portion. The lateral overlying tongue portion protrudes along a direction from the right side to the left side in a front surface side. The siding boards are attached to the underpayment. The securing metal fitting is disposed at the opposite upper and lower sides of the siding boards in order to fix the siding boards. The sealing member is disposed between left and right adjacent siding boards, having a base plate portion, a rising plate portion, a front plate portion and a front resilient material. The base plate portion is secured to the underlayment. The rising plate portion is bent forward from the base plate portion and abuts against a side surface of the lateral underlying tongue portion of the siding board. The front plate portion is bent from a front end of the rising plate portion in the opposite direction from the base plate portion. The front resilient material is provided on a front surface of the front plate portion. The front plate portion engages with a front surface of the lateral underlying tongue portion of the siding board. The front resilient material is in tight contact with a front inner surface of the notched recess and a back surface of the lateral overlying tongue portion of the siding boards.
According to another aspect of the invention, a sealing member used for a siding boards attachment structure, includes a base plate portion, a rising plate portion, a front plate portion and a front resilient material. The base plate portion is configured to be secured to an underlayment. The rising plate portion is bent forward from the base plate portion and is configured to abut against a side surface of the lateral underlying tongue portion. The front plate portion is bent from a front end of the rising plate portion in the opposite direction from the base plate portion and configured to engage with a front surface of the lateral underlying tongue portion of the siding board. The front resilient material is provided on a front surface of the front plate portion and configured to be in tight contact with a front inner surface of the notched recess of one of the siding board and a back surface of the lateral overlying tongue portion of the other siding board.
According to the other aspect of the invention, a siding board used for a siding boards attachment structure includes opposite right and left sides and opposite upper and lower sides, a lateral underlying tongue portion, a lateral overlying tongue portion and a notched recess. The lateral underlying tongue portion and the lateral overlying tongue portion are provided at the opposite right and left sides, respectively. The lateral underlying tongue portion protrudes along a direction from the left side to the right side in a back surface side. The lateral overlying tongue portion protrudes along a direction from the right side to the left side in a front surface side. The notched recess is notched along a direction from the right side to the left side in front of the lateral underlying tongue portion. The notched recess is formed such that portions of the front resilient material and the front plate portion of the sealing member can be fitted into the notched recess.
According to yet another aspect of the invention, a method of attaching siding boards, includes disposing securing metal fittings on the opposite upper and lower sides of a first row siding board, disposing the first row siding board on the underlayment using the securing metal fittings, bringing the rising plate portion of the sealing member into abutment against the lateral overlying tongue portion of the first row siding board, engaging the front plate portion of the sealing member with a front surface of the lateral underlying tongue portion, fitting the front resilient material and the front plate portion of the sealing member into the notched recess of the first row siding board, bringing the front resilient material into tight contact with a front inner surface of the notched recess, securing the sealing member to the underlayment, disposing the securing metal fitting on the opposite upper and lower sides of a second row siding board, disposing the second row siding board to the underlayment such that the sealing member is sandwiched between the first row siding board and the second row siding board, and bringing the front resilient material into tight contact with a back surface of the lateral overlying tongue portion of the second row siding board.